Air
Source Heat Pumps

Air source heat pumps absorb heat from the outside (ambient) air and transfer it to water in the insulated storage tank.

They can look similar to a conventional electric hot water heater, but a little taller or they can look like air conditioning units. This depends on if they are integrated heat pumps or split system heat pumps.

Both types of heat pumps are remarkably efficient in warm and humid climates, and specific models work really well in cold climates too. (Just tell us your postcode when you call and the number of people in your house, and that will be a great start to getting you a cost saving highly efficient low carbon footprint dependable hot water system!).

You know the saying "use the right tool for the job"... there are many heat pump models to choose from, and some will work for you and you'll be extremely happy and others won't meet your needs and everyone will be grumpy.

When do air source heat pumps work at their best?

Unlike solar hot water heaters, they heat your hot water in complete darkness nearly as efficiently as they do in full sunshine.

When a solar hot water system is struggling during the short sunlight days during winter, a hot water heat pump still blissfully chugs away.

Is there any boosting required?

The best technology air source heat pumps do not require any boosting, unlike solar water heaters which rely upon electric elements or gas burners to reheat your hot water tank when the sun goes down after heavy hot water usage or on cloudy days even with minimal usage.

Unfortunately these solar hot water systems are only working at maximum efficiency (and at lowest cost) on sunny days with maximum daylight hours.

In the southern states of Australia this is between 50% to 70% of the full year. The rest of the year the electric or gas booster system is actively working as fast as electricity and gas prices are rising.

The point is you need the right system to meet the needs of your household, and that depends on how many of you there are, where you live, how many appliances are hooked up to your hot water service (and if you have teenagers!)

What factors affect their operation?

There are a number of factors which affect the efficiency of an air source heat pump. The most influential are the outside air temperature, the temperature of the cold water entering the storage tank to be heated, and the timing and quantity of hot water drawn off during a 24 hour period.

The colder the water entering the storage tank, the higher amount of energy is required to raise it to the standard 60°C. The warmer the air outside, the more heat can be drawn by the heat pump unit to heat the water in the tank. Same goes for humidity. The higher the usage at the coldest time of day, the longer it will take to replenish a full tank of hot water.

With ground source heat pumps, the inlet temperature of the water entering the tank is relatively constant throughout the year. With air source heat pumps you are drawing water into the tank from the same pipework as the rest of your house. Throughout the year the temperature of the water in the pipes varies, and in really cold climates ground source heat pumps may have an efficiency advantage over air sourced heat.

Importantly you will know, that at night time or on cloudy days there won't be a booster element running up your power bills like an electric or solar electric/solar gas hot water service.

These are general principles. There are some heat pumps where the technology allows for the same reheating rate irrespective of ambient air temperature – the compressor varies its work-rate in such a way as to deliver a near constant reheating rate.

Depending on your circumstances these models may be best for you, and the difference in cost is just a few hundred dollars. In most cases, they are not a necessity, but if you want the best reheating rate technology, please call us today and we'll get your questions answered.

They still require electricity to run don't they?

Yes, an air source heat pump will be drawing electricity, but at a rate 70% to 80% less than solar/electric, solar/gas boosted models.

And for larger households of 4 or more people, they are even less costly to run than the most efficient natural gas water heaters, and almost definitely cheaper to purchase and install.